環(huán)境工程專業(yè)畢業(yè)設(shè)計(jì)外文翻譯

1、<p><b>　　目 錄</b></p><p><b>　　介紹：1</b></p><p><b>　　1實(shí)驗(yàn)性2</b></p><p>　　1.1污水和活性污泥2</p><p>　　1.2實(shí)驗(yàn)性設(shè)定和過程3</p><p&g

2、t;　　1.3測(cè)試和監(jiān)視抽樣采取從混雜的醇中過濾4</p><p><b>　　2.結(jié)果5</b></p><p>　　2.1泥漿化顆?；?</p><p>　　2.2 EGSB操作流出物的穩(wěn)定酸堿度6</p><p>　　3 .TPD污水的理論演算和討論7</p><p>　　3.1酸

3、平衡和中間轉(zhuǎn)換能力酸堿度7</p><p>　　3..2 VFA在厭氧過程用二種主要方式的二個(gè)主要小組細(xì)菌介入降低有機(jī)基體…………..8</p><p>　　3..3 VFA和強(qiáng)堿性平衡強(qiáng)堿性的典型的變異………………………………………………..8</p><p><b>　　4.結(jié)論9</b></p><p><

4、;b>　　命名原則10</b></p><p><b>　　參考文獻(xiàn)10</b></p><p>　　Introduction12</p><p>　　1 Experimental14</p><p>　　2 Results16</p><p>　　3 Theoret

5、ical calculation and discussions19</p><p>　　4 Conclusions22</p><p>　　recomference:23</p><p>　　穩(wěn)定性的膨脹的顆粒狀污泥床</p><p>　　對(duì)滌綸人造絲印染廢水的處理</p><p><b>　　摘要&

6、lt;/b></p><p>　　滌綸人造絲印染污水(TPD污水)，包含平均7.0mg/L對(duì)苯二甲酸（技術(shù)援助）作為主要碳來源和特性污染物，從屬于膨脹的顆粒狀污泥床(EGSB)過程。EGSB過程的穩(wěn)定由實(shí)驗(yàn)室實(shí)驗(yàn)首先研究了。TA電離是影響系統(tǒng)的酸基度平衡的優(yōu)勢(shì)的因素。廢水的 TA 的高集中造成充份的緩沖能力使中立脂肪酸 (VFA) 從培養(yǎng)基降格產(chǎn)生而且提供了沒有空氣而能生活強(qiáng)的系統(tǒng)揮發(fā)性基礎(chǔ)抵抗 pH 減少

7、 到低于6.5 。揮發(fā)性脂肪和不飽和脂肪酸除每小時(shí)次于6.35和揮發(fā)性脂肪積極從事它的極大值以外幾乎沒有抑制上去沼氣生產(chǎn)。與顆?；患せ畹奈勰嘁黄?有機(jī)撤除效率和沼氣的生產(chǎn)率逐漸增加了和變得更加穩(wěn)定。在啟動(dòng)后,COD撤除效率增加到57%-64%,酸堿度被穩(wěn)定在范圍的7.99～6.04,和沼氣的生產(chǎn)率是相對(duì)高。酸堿度污泥顆?；?適當(dāng)?shù)牧魅胛锖脱b載使EGSB過程穩(wěn)定。EGSB反應(yīng)器是穩(wěn)定的為TPD廢水處理。</p><

8、p>　　關(guān)鍵詞:膨脹的顆粒狀泥床;穩(wěn)定;絕氧處理;印染污水</p><p><b>　　介紹：</b></p><p>　　為了獲得柔韌的和優(yōu)雅的如絲一樣滌綸結(jié)構(gòu)、滌綸本色布總是同堿分解過程被預(yù)先處理, NaOH以某一溫度和壓力滌綸纖維被水解在某種程度上。在這個(gè)過程期間,表面滌綸纖維從本色布料上被溶化,滌綸酸(TA)和1,2-亞乙基二醇被釋放作為污水中主要污染物

9、。獲得的充滿絲質(zhì)皺痕和軟質(zhì)感滌綸織品叫做人造絲織品。滌綸的堿分解可能由化工等式描述如下。</p><p>　　污水堿分解過程與污水混合了從打印，洗染，漂洗和其他過程被命名為滌綸人造絲印染的污水(T/D污水)。只在中國(guó)東部紹興縣, ,那里每天釋放超過300數(shù)以萬計(jì)噸TPD污水。雖然缺氧的或好氧的生化處理已經(jīng)作為通常的預(yù)先為處理的這種廢水的方法。多樣的曝氣過程結(jié)構(gòu)也是它們的一種用法。然而廣泛應(yīng)用的曝氣過程已經(jīng)妨害由缺

10、乏了解到相關(guān)因素穩(wěn)定性的生物進(jìn)程包括去除系數(shù)的有機(jī)底質(zhì)、沼氣生產(chǎn)比率和另一些指標(biāo)。那個(gè)包含于穩(wěn)定性加工的、依靠酸堿平衡特征污染物在噸/日廢水的TA是一種二重的有機(jī)酸、存在于進(jìn)水形成分子或離子狀態(tài)。酸堿平衡在厭氧的體系是靜止的大約是由于TA的效果。那展開粒狀污泥床（egsb）處理發(fā)展從上流式厭氧污泥層處理、是一個(gè)有較高的比率和有害的阻力的厭氧控制處理方法。未來的egsb技術(shù)發(fā)展的由于噸/日廢水處理依賴透處理的穩(wěn)定性。處理的穩(wěn)定性是論述、酸

11、堿平衡是強(qiáng)調(diào)和實(shí)驗(yàn)室實(shí)驗(yàn)是傳導(dǎo)。</p><p><b>　　1實(shí)驗(yàn)性</b></p><p>　　1.1污水和活性污泥</p><p>　　因?yàn)?650噸/日TPD廢水在紹興縣、浙江省、瓷器在最上級(jí)全年的調(diào)查以后廢水在實(shí)驗(yàn)中是降低那中央的泵站處理率、主要的指標(biāo)是廢水中的污染物是TPD廢水以每小時(shí)化學(xué)需氧量高、化學(xué)需氧量和色度為特征，與傳統(tǒng)的印

12、染廢水COD從780mg／L的到3116mg／L的量不同；和生物需氧量因?yàn)椋ㄎ迦丈柩趿浚?25mg／L的到1436mg／L不同，TA從286mg／L的到1279mg／L不同。特征污染物控制在4068COD的3650噸/日廢水活性污泥實(shí)驗(yàn)是從殺蟲劑廢水、印染廢水和石炭酸廢水污泥處獲得。處理設(shè)備在實(shí)驗(yàn)室厭氧的反應(yīng)器和egsb反應(yīng)器到保持高濃度的生物資源的情況一樣。</p><p>　　1.2實(shí)驗(yàn)性設(shè)定和過程&l

13、t;/p><p>　　圓柱狀的EGSB反應(yīng)器被劃分了成四隔間(圖2):</p><p>　　(1)粒狀污泥積聚區(qū)；（２）液化區(qū)；（３）三相分離器（４）粒狀污泥床。在那粒狀污泥床上、由于廢水在粒狀污泥的再循環(huán)床和液化區(qū)，所以液化區(qū)發(fā)展主要是生物降解發(fā)生和沼氣生產(chǎn)的地方。當(dāng)做混合溶液穿過氣體液體固體分離器、那污泥穿過分離器的孔到那液化區(qū)和污泥場(chǎng)、在一些絮凝和分散污泥泥沉淀反應(yīng)器同流出的的時(shí)候、那表

14、面水流變成存儲(chǔ)器從堰流出，并且沼氣流入一濕式氣體流量計(jì)反應(yīng)器。反應(yīng)器(圖2)是1.5米高的與流化的區(qū)域和污泥床f7.0升有效的容積和2.0升的設(shè)置隔間。</p><p>　　實(shí)驗(yàn)性設(shè)定的一張概要圖被顯示在圖31為了從消除高酸堿度和短缺N和P,培養(yǎng)的污水中第一次集中調(diào)整了COD:N:P=200:5:1。在污水水庫被增加氫磷酸鹽和氨硫酸鹽和增加稀釋鹽酸在中立化反應(yīng)器由滴定器控酸堿度=10.0。泵被連續(xù)使用提供污水給E

15、GSB反應(yīng)器中混雜的積累污泥有能力在碳上退化。反應(yīng)溫度被加熱器和溫度調(diào)解器控制了。酸堿度被定器(DL55,Mettler?Toledo,德國(guó))監(jiān)測(cè)了和調(diào)整了。而滴溫度一根熱探針連接到一臺(tái)紅外光芒加熱器所確定。其它項(xiàng)目的根據(jù)標(biāo)準(zhǔn)方法(中國(guó)1997環(huán)境保護(hù)局編輯委員會(huì)) 進(jìn)行了測(cè)試。在EGSB反應(yīng)器的起動(dòng)期間,磷酸鹽和碳酸鹽包含F(xiàn)e、Al,Ni等增加入混雜的礬花提高被激活的污泥顆粒化。TPD流入物使污水比率逐漸增加到100%。過程穩(wěn)定被重視

16、當(dāng)起動(dòng)由逐步增加舉辦了污泥負(fù)荷和水力負(fù)荷。在EGSB反應(yīng)器起動(dòng)期間,它被管理在流入物酸堿度6.3～6.8和水力裝載0.002～64m3/(m3d)和往上流動(dòng)線性速度0-2.0m/h,與溫度被控制在33～6(Table2)。通常,開始階段為厭氧過程能被定義作為過渡階段在反應(yīng)器之前平穩(wěn)地運(yùn)轉(zhuǎn)。參量表明反應(yīng)器表現(xiàn)在起動(dòng)期間</p><p>　　1.3測(cè)試和監(jiān)視抽樣采取從混雜的酒立刻被過濾了</p><

17、;p>　　對(duì)TA的分析是用一臺(tái)高性能液體色譜分析儀(HPLC,Gilson,法國(guó))測(cè)定的。運(yùn)行以流動(dòng)相(v/v)在58/42,和加法2～6被集中的H3PO4每公升。分離進(jìn)行在1.5ml/min流速和專欄溫度25～6使用ODS218反回階段column(Alltech,美國(guó))。一臺(tái)紫外探測(cè)器以波長(zhǎng)在254毫微米被使用了。測(cè)量出來,TA保留時(shí)間是在4.57～6.63分鐘。</p><p><b>　　

18、2.結(jié)果</b></p><p><b>　　2.1泥漿化顆?；?lt;/b></p><p>　　泥漿化顆?；⑶褽GSB反應(yīng)器起動(dòng)起動(dòng)是EGSB反應(yīng)器爛泥的過程顆?；?Hulshoff1986) 的根本。起動(dòng)經(jīng)常采取2～6幾個(gè)月,長(zhǎng)期的有一年(Juragen1990)。流入物COD和TA是各自地受控在1250～61943mg/L和563～6.41mg/L,。

19、水力負(fù)荷對(duì)對(duì)污泥穩(wěn)定進(jìn)行了調(diào)整。圖4顯示污泥在反應(yīng)器起動(dòng)期間在30天和60天特征。被激活的污泥看來分明是異種的反應(yīng)器,能被劃分成污泥床,污泥暫停的區(qū)域并且設(shè)置區(qū)域在天60.Granular爛泥直徑是1.0毫米占領(lǐng)超過在EGSB反應(yīng)器里60天的總爛泥的10%。</p><p>　　反應(yīng)器中基體含量被顯示在圖5。在0.4m高度之上,COD集中在設(shè)置區(qū)域。從底部對(duì)0.4反應(yīng)器的m軸向高度,COD集中退出了。COL出現(xiàn)同

20、COD一樣。COD撤除效率增加了從23.6%在30天到49.1%在60,天和COL撤除效率被增加從60%在30天到75.0%在60天。反應(yīng)器表現(xiàn)改變了污泥顆?；?。EGSB反應(yīng)器為TPD廢水處理通常起動(dòng)器。生物降解首要發(fā)生了在污泥床,并且外部圈導(dǎo)致密集混合污水在EGSB反應(yīng)器里。</p><p>　　2.2 EGSB操作流出物的穩(wěn)定酸堿度</p><p>　　使用表明EGSB反應(yīng)器COD去除

21、效率(～6COD)并且沼氣生產(chǎn)率(Vg,相當(dāng)數(shù)量沼氣從1公斤COD去除在標(biāo)準(zhǔn)狀態(tài)之下)。圖6顯示EGSB的表現(xiàn)變異在起始的期間。從10天到28天,TPD污水在流入物成比例地增加?！?COD的第一高峰價(jià)值被提出了在15天和20天之間,與Vg0.11～6.18m3/(kgCOD)。COD去除效率和沼氣生產(chǎn)率是不穩(wěn)定的,和TPD污水流入物在過量地增加了。從28天,流入物是所有TPD污水。在30天和45天之間,流出物酸堿度是7.45～6.05～

22、6COD是36%～69%并且Vg是0.015～6.20m3/(kgCOD)。流出物酸堿度、～6COD和Vg的變異是在45天之前卓越的。這是一個(gè)分化期間為被激活的污泥。在45天以后,流出物酸堿度被穩(wěn)定在7.99～6.04～6。COD的范圍增加到57%～64%,Vg并且保留了0.12～6.17m3(的穩(wěn)定的價(jià)值kgCOD)。實(shí)際上,從45天,粒子污泥從污泥中被區(qū)分,EGSB反應(yīng)器提出了它的更好的穩(wěn)定。顆粒狀污泥被測(cè)量,彌補(bǔ)了總污泥的在60天

23、10%。當(dāng)只采取了反應(yīng)器cubage的25%污泥床被填滿以總污泥的65%。EGSB反應(yīng)器</p><p>　　3 .TPD污水的理論演算和討論</p><p>　　3.1酸平衡和中間轉(zhuǎn)換能力酸堿度</p><p>　　酸平衡和中間轉(zhuǎn)換能力酸堿度是最重要的參量。當(dāng)中一個(gè)表明厭氧系統(tǒng)的穩(wěn)定。細(xì)菌的最佳的酸堿度為從6.5到7.5(Souza1986)。當(dāng)VFA積累導(dǎo)致酸堿

24、度減退,厭氧處理的效率明顯已經(jīng)下降(顧1993)。所以,它在厭氧系統(tǒng)對(duì)控制VFA是比對(duì)控制酸堿度重要。強(qiáng)堿性被看成如同抵抗VFA儲(chǔ)積一個(gè)重要角色以便增加一個(gè)厭氧系統(tǒng)酸堿度 (Kroeker1979年;顧,1993)。污水的強(qiáng)堿性被定義作為可能適合與強(qiáng)的酸的起反應(yīng)總物質(zhì)。強(qiáng)堿性包括許多堿組分譬如碳酸鹽、重碳酸鹽、含水物和有機(jī)基物。它們?cè)谖鬯?叫作為總強(qiáng)堿性中國(guó)1997環(huán)境保護(hù)局編輯委員會(huì))。TPD污水有復(fù)雜組分并且碳酸鹽、重碳酸鹽和含水

25、物的集中無法適當(dāng)被獲得。如此總強(qiáng)堿性在污水被使用來作為重大顯示為基本的組分。共同地,混雜的酸2基點(diǎn)平衡在厭氧反應(yīng)器里由電離平衡氨、VFA和碳酸鹽控制(KroekerEJ1979年;張,1997)。氨電離平衡作為等式(2):NH3H2.O=NH++OH-。(2)當(dāng)[H+]增加,酸堿度減少并且平衡轉(zhuǎn)移在右邊。在35～6,電離常數(shù)是1.85～60-5VFA通常由乙酸和酸組成。因?yàn)槎FA有接近的電離常數(shù),電離平衡</p><

26、;p>　　3.2 VFA在厭氧過程用二種主要方式的二個(gè)主要小組細(xì)菌介入降低有機(jī)基體</p><p>　　在第一階段對(duì)揮發(fā)性脂肪酸(VFA)水解和降低復(fù)雜有機(jī)基體。在第二階段,VFAs由細(xì)菌運(yùn)用并且導(dǎo)致甲烷氣產(chǎn)生。二個(gè)過程同時(shí)發(fā)生并且過程穩(wěn)定取決于在二個(gè)主要階段之間有機(jī)基體細(xì)微生物化學(xué)的平衡。厭氧處理不穩(wěn)定通常以由VFAs的集中的迅速增量而甲烷氣生產(chǎn)的隨后減退表明。有許多因素與相關(guān)不穩(wěn)定或過程破壞。例如,甲烷

27、的不足的生理適應(yīng)對(duì)新基體、迅速溫度或酸堿度波動(dòng)。從結(jié)果由Kroeker等。(Andrews1969年;Kroeker,1979),厭氧消化毒力與揮發(fā)性酸的過份集中關(guān)系了(UFAs)更加直接,雖然它們與過份游離氨含量大概間接地關(guān)系了。而且,以由于膜法酸堿度比其它化合物容易擊穿通過細(xì)胞膜毒力有一種接近的交互作用。當(dāng)微生物同化污泥，酸堿度使細(xì)胞迅速地下降并且微生物的新陳代謝率減少。它是可接受的,作試驗(yàn)者毒力由膜法造成在集中在30到60mg/L

28、之上作為乙酸。</p><p>　　3.3 VFA和強(qiáng)堿性平衡強(qiáng)堿性的典型的變異</p><p>　　VFA和強(qiáng)堿性平衡強(qiáng)堿性的典型的變異和VFA在EGSB反應(yīng)器里被顯示在圖11。缺氧流出物的強(qiáng)堿性集中與TPD污水在900～6000mg/L的范圍近似地相等的。反彈范圍是大約100mg/L。在EGSB的處理以后總強(qiáng)堿性集中增加了大約250mg/L到1150～6250mg/L。流入物(TPD污

29、水)VFA90～633mg/L增加到197～636mg/L在缺氧處理以后,當(dāng)流出物VFA以去除效率79.1%～62.1%從EGSB反應(yīng)器是19.8～63.2mg/L?？倧?qiáng)堿性增量在EGSB反應(yīng)器里能被假定與VFA的消耗量相關(guān)。</p><p>　　強(qiáng)堿性是在厭氧系統(tǒng)緩沖抵抗VFA能力。污水的VFA幾乎抑制不了厭氧過程。強(qiáng)堿性的集中是緩沖VFA足夠高的混雜的醇。Lesilie(Lesilie1989)采取為VFA比

30、與總強(qiáng)堿性評(píng)估緩沖厭氧能力system(Leslie,1989)?？倧?qiáng)堿性輕微只下降了在缺氧治處理期間和在EGSB反應(yīng)器里輕微登升高。VFA的定量對(duì)total2.alkalinity比0141VFA比和總強(qiáng)堿性與相關(guān)厭氧系統(tǒng)的穩(wěn)定被顯示在表3 (Leslie1989)。明顯地, 當(dāng)TPD污水在EGSB反應(yīng)器里處理時(shí)VFA集中的變異只導(dǎo)致了酸堿度的少量變化?；祀s的醇的緩沖能力在EGSB過程是充足的。</p><p>

31、;<b>　　4.結(jié)論</b></p><p>　　TA,二重的有機(jī)酸因?yàn)樗釅A平衡對(duì)那堿度的那廢水供應(yīng)充分的緩沖量，當(dāng)EGSB加工被用于處置TPD廢水，與污泥顆粒一起作用，EGSB反應(yīng)器性能改善和變成更穩(wěn)定。</p><p><b>　　命名原則</b></p><p>　　BOD5:五日生化需氧量,mg/L;SS:懸浮固

32、體;COD:化學(xué)氧需求,mg/L;VFA:揮發(fā)性脂肪酸;COL:顏色;UFA:不飽和脂肪酸;EGSB:膨脹的顆粒狀爛泥床;Vg:沼氣生產(chǎn)率,m3/(公斤COD);HRT:水力保留時(shí)間,h;T:溫度～6;K:電離常數(shù);TA;MLSS,g/L;～ηCOD:化學(xué)需氧量除去;PVA:聚乙烯醇。</p><p><b>　　參考文獻(xiàn)</b></p><p>　　[1 ] And

33、rews J F , 19691 Dynamic model of the anaerobic digestion process [ J ] .</p><p>　　Sanitary Engineering Division ASCE , 95 (SA1) : 95 6161.</p><p>　　[2 ]Capri M G, Marais G V R , 19751 pH adjust

34、ment in anaerobic digestion [ J ] .</p><p>　　Water Research , 9(3) : 307 6131.</p><p>　　[3 ]Editorial Board of Encyclopedia of Chemical Industry , 19901 Encyclopedia of</p><p>　　che

35、mical industry[M] . Vol 11 Beijing.</p><p>　　[4 ]Chemical Industry Press. Editorial Board of Environment Protection Bureau of China , 1997.1.</p><p>　　[5 ]Monitoring and determination methods fo

36、r water and wastewater [M] . 3rd. ed. Beijing : China Environmental Science Press.Guan B H , Wu ZB , Wu Z C et al . , 2003.1 .</p><p>　　[6 ]Gu X S , 19931 Mathematical model for wastewater bio-treatment [M]

37、. 2nd ed. Beijing : Tsinghua University Press. Hulshoff P L , Lettinga G, 1986.1 .</p><p>　　[7 ]New technologies for anaerobic treatment [J ] . Water Science and Technology , 18 (2) : 41 631 Juragen H T , Wu

38、 WM, Mahendra KJ , 1990.1 .</p><p>　　[8 ]Ecoengineering high rate anaerobic digestion systems : Analysis of improved syntrophic biomethanation catalysts [J ] . Biotechnology and Bioengineering , 35 (10) : 99

39、0 6991 Kroeker E J , Schulte D D , Sparling A B et al . , 1979.1. </p><p>　　[9 ]Anaerobic treatment process stability[J ] . J Water Pollution Control Federation , 51 (4) : 718 67271 Leslie G C P , Henry C L

40、, 1989.1 .</p><p>　　[10 ]Biological wastewater treatment : Theory and application(Li , X.W. , Yang , X. K. , Zhang , Y. G. ed. ) [M] . Beijing : China Architecture and Building Press. Souza M E , 1986.1. <

41、;/p><p>　　[11 ]Criteria for the utilization , design and operation of UASB reactors[J ] . Water Science and Technology , 18 (12) : 55 661 Zhang X, Wang B Z , Zhu H , 1997.1. </p><p>　　[12 ]The Acid

42、2alkaline equilibrium and buffer capacity of anaerobic digestion system[J ] . China Environmental Science , 17 (6) : 492 6951.</p><p>　　[13 ]Biodegradability of terephthalic acid in terylene artificial silk

43、printing and dyeing wastewater [ J ] . Journal of Environmental Sciences , 15(3) : 296 6011.</p><p>　　Stability of expanded granular sludge bed process for terylene artificial silk printing and dyeing wastew

44、ater treatment</p><p><b>　　Abstract</b></p><p>　　Terylene artificial silk printing and dyeing wastewater (TPD wastewater), containing averaged 7.0 mg/L terephthalic acid (TA) as the

45、main carbon source and the character pollutant, was subjected to expanded granular sludge bed (EGSB) process. The stability of the EGSB process was firstly conducted by laboratory experiment. TA ionization was the predom

46、inated factor influencing the acid-base balance of the system. High concentration of TA in wastewater resulted in sufficient buffering capacity to </p><p>　　Keywords: expanded granular sludge bed; stability;

47、 anaerobic treatment; dyeing and printing wastewater</p><p>　　Introduction：</p><p>　　In order to obtain pliable and elegant terylene fabric just like silk, terylene greige cloth is always pretre

48、ated with alkali-decomposition process, wherein terylene fiber is hydrolyzed to some extent in NaOH solution at certain temperature and pressure. During this process, the superficial terylene fibred is peeled off from th

49、e greige cloth and dissolved into solution, in which terylene acid (TA) and ethylene glycol are discharged as the main pollutants in wastewater. The obtained terylene fabr</p><p>　　The wastewater from the al

50、kali-decomposition process mixed with wastewater from printing, dyeing, potch and the other processes is named terylene artificial silk printing and dyeing wastewater ( T/D-wastewater ) . Only in Shaoxing County, East Ch

51、ina, are there more than 300 thousands tons TPD-wastewater discharged each day.</p><p>　　Although the anoxic or aerobic bio-process has been the usual approach for the treatment of such kind of wastewater, v

52、arious anaerobic process configurations were also found their usage in this field. However, the widespread application of anaerobic process has been hampered by the lack of understanding of factors associated with stabil

53、ity of the biological processes involved. The removal efficiency of organic substrates , the biogas production rate and the other items , which are involved in th</p><p>　　The expanded granular sludge bed (

54、EGSB) process developed from UASB process , is one of the controlled anaerobic treatment processes with advantages of higher rate and better toxic resistance. Although EGSB process has the efficiency of 27.1 % 68.0 % for

55、 chemical oxygen demand ( COD) removal and 31.4 % 66.0 % for TA removal</p><p>　　(Guan , 2003) , further development of EGSB technology for TPD-wastewater treatment depends upon a better understanding of the

56、 process stability. In this paper , the stability of the process was discussed , the acid-base balance was emphasized and lab scale experiments were conducted.</p><p>　　1 Experimental</p><p>　　

57、1.1 Wastewater and activated sludge</p><p>　　The wastewater in the experiment was taken from the central pump station for 3 605 t/d TPD wastewater in Shaoxing County , Zhejiang Province , China. After a one

58、-year round survey , the main pollutants in the wastewater are given in Table 11 TPD wastewater characterized by high pH , COD value and color (COL) is different from traditional printing and dyeing wastewater. The value

59、 of COD varies from 780 mg/L to 3116 mg/L ; and biological oxygen demand for 5 d (BOD5 ) from 325 mg/L to 1436 mg/L. TA</p><p>　　40 % 68 % of the total COD in TPD wastewater. Activated sludge for the experim

60、ent was obtained from the treatment facility for pesticide wastewater , printing and dyeing wastewater and phenol wastewater. Sludge was acclimated firstly in a laboratory anaerobic reactor running in a fill and drawn mo

61、de under the same conditions as EGSB reactor to retain high concentration of biomass.</p><p>　　1.2 Experimental set-up and process</p><p>　　The columned EGSB reactor was divided into four compa

62、rtments (Fig. 2) : (1) the granular sludge bed in which the granulated sludge was accumulated ; ( 2) the fluidized zone in which sludge was suspended ; (3) the gas-liquid- sludge separator ; and (4) the setting zone. The

63、 influent and reflux from the recycle pump was pumped into the bottom of the reactor and passed through the granular sludge bed.</p><p>　　Above the granular sludge bed , a fluidized zone developed mainly due

64、 to wastewater recycle. In the granular sludge bed and fluidized zone , the biological degradation took place and the biogas was produced. As mixed liquor passed through the gas-liquid-solid separator , the sludge with g

65、ood setting abilities settled back through the apertures of the separator to the fluidized zone and sludge bed , while some flocculated and dispersed sludge was washed out of the reactor with effluent , the effl</p>

66、;<p>　　A schematic drawing of the experimental setup is shown in Fig. 31 In order to eliminate the inhibition from high pH and shortage of N and P , the feeding wastewater was first adjusted to the concentration o

67、f COD:N:P = 200:5:1 in wastewater reservoir by adding dipotassium hydrogen phosphate and ammonia sulfate and pH =10.0 by adding dilute hydrochloric acid in a neutralization reactor controlled by titrator. A pump was used

68、 to supply wastewater continuously to EGSB reactor charged with mixed accu</p><p>　　The pH was monitored and adjusted with a titrator (DL55 , Mettler Toledo , Germany ) . Temperature was determined with a th

69、ermo probe connected to an infrared ray heater. Test of the other items was conducted according to the standard methods ( Editorial Board of Environment Protection Bureau of China , 1997) .</p><p>　　During t

70、he start-up of the EGSB reactor , phosphate and carbonate containing Ca , Fe , Al , Ni etc. were added into mixed liquor to enhance the granulating of the activated</p><p>　　sludge. The ratio of TPD wastewat

71、er in the influent was gradually increased to 100 %. The stability of the process was valued while start-up was conducted by increasing sludge</p><p>　　loading and hydraulic loading step by step. During the

72、EGSB reactor start-up , it was operated at influent pH 6.3 6.8 and hydraulic load 0.002 64 m3/(m3</p><p>　　d ) and up-flow linear velocity 0 —2.0 m/h , with temperature controlled at 33 ℃(Table 2) . Generall

73、y , start-up stage for anaerobic process could be defined as the transitional stage before the reactor working steadily. The parameters indicating reactor performance during start-up include removal efficiencies of pollu

74、tants , biogas production rate , variation of pH , concentration of VFA and so on. After the EGSB reactor start-up , it was operated at a Flow-rate about 7.5 LPd and HRT 32 h in EG</p><p>　　neutralization re

75、actor , while the hydraulic loading 22 609 m3/(m3 d) and up-flow linear velocity 1.0 6.0 m/h and temperature was controlled at 33 ℃( Table 2) . Stability of anaerobic reactor was valuated with COD removal efficiency , bi

76、ogas production rate and pH value. All of these parameters involved in the stability depended on the acid-base balance in the reactor. So total-alkalinity , VFA and TA concentration were also tested.</p><p>

77、　　1.3 Test and monitoring</p><p>　　Samples taken from mixed liquor were filtered immediately. Analysis of TA was carried on a high performance liquid chromatograph (HPLC , Gilson , France) . Aliquots of 25

78、℃were injected to the HPLC , running with mobile phase of acetonitrile/water ( v/v) at 58/42 , and an addition of 2祃 of concentrated H3 PO4 per liter of solution. The separation was performed using an ODS218 reversed pha

79、se column(Alltech , USA) at the flow-rate of 1.5 ml/min and column temperature of 25 ℃. An UV detector was us</p><p><b>　　2 Results</b></p><p>　　2.1 Sludge granulating and EGSB reac

80、tor start-up</p><p>　　The start-up is a process of sludge granulating that is essential for EGSB reactor (Hulshoff , 1986) . Start-up often takes 2 6 months , even as long as one year (Juragen , 1990) . The

81、influent COD and TA were controlled at 1250 61943 mg/L and 563 6.41 mg/L , respectively. The hydraulic loading was adjusted to suit for sludge settling</p><p>　　back. Fig. 4 shows the sludge characteristics

82、along the axis at the day 30 and the day 60 during reactor start-up. Activated sludge appeared to be heterogeneous distinctly along the axis of reactor , in which could be divided into sludge bed , sludge suspended zone

83、and setting zone at the day 60.Granular sludge which diameter is over 1.0 mm occupied more than 10 % of total sludge in EGSB reactor at the day 60.</p><p>　　The substrate concentration along reactor axis is

84、shown in Fig. 5. Above 0.4 m height , COD concentration at different height closed extremely to each other except in setting zone. From the bottom to 0.4 m axial height of the reactor , COD concentration stepped down ext

85、remely. The COL appeared the same as the COD. Removal efficiency of</p><p>　　COD increased from 23.6 % at the day 30 to 49.1 % at the day 60 , and the removal efficiency of COL increased from 60 % at the day

86、 30 to 75.0 % at the day 60. The reactor performance changed with the sludge granulating. The EGSB reactor for TPD wastewater treatment started up normally. The biodegradation occurred chiefly in sludge bed , and the out

87、side loop resulted in intensive mixing of wastewater in EGSB reactor.</p><p>　　2.2 Stability of the EGSB operation</p><p>　　Effluent pH , COD removal efficiency (ηCOD) and biogas production rat

88、e ( Vg , amount of biogas from 1 kg COD removal under standard state) were used to indicate the EGSB</p><p>　　reactors performance. Fig. 6 shows the performance variation of EGSB during start-up period. From

89、 the day 10 to the day 28 , TPD wastewater in influent increased proportionally. The first peak value of ηCOD was presented between the day 15 and the day 20 , with Vg 0.11 6.18 m3/(kgCOD) . The efficiency of COD removal

90、 and the biogas production rate were much unstable , and decreased sharply when TPD wastewater in influent increased excessively.</p><p>　　From the day 28 , influent was all of the TPD wastewater. Between th

91、e day 30 and the day 45 , effluent pH was 7.45 6.05 , ηCOD was 36 %69 % and Vg was 0.015 6.20 m3/( kgCOD) . The variation of effluent pH , ηCOD and Vg were remarkable before the day 45. It was a differentiation period fo

92、r activated sludge.</p><p>　　After the day 45 , effluent pH stabilized in a range of 7.99 6.04 ,ηCOD increased to 57 %64 % , Vg also kept a stable value of 0.12 6.17 m3P( kgCOD) . In fact , from the day 45 ,

93、 the granule sludge differentiated from sludge , and EGSB reactor presented its better stability. It was measured that granular sludge was made up of 10 % of the total sludge at the day 60. The sludge bed was charged wit

94、h the 65 % of the total sludge while only took -5 % of the reactor cubage. EGSB reactor抯 performance i</p><p>　　56.0 %(Guan , 2003) . The EGSB reactor kept in halted state for 45 d at the temperature of 20 6

95、5 ℃after three months operation. Fig. 7 illustrates the reactor restart . The biogas production rate increased step by step. The COD removal was relatively stable with efficiency of 40 %60 %. The reactor restart only too

96、k 12 d. After maximum turnover rates of COD averaged 60 % , the system was switched to a load shocking with higher hydraulic load as much as 200 % of the normal load at the day 16. The </p><p>　　3 Theoretica

97、l calculation and discussions</p><p>　　3.1 Acid-base balance and buffering capability of TPDWastewater</p><p>　　The pH is one of the most important parameters indicating the stability of anaerob

98、ic system. The best pH for methanogenic bacteria is from 6.5 to 7.5 ( Souza , 1986) .</p><p>　　While VFA accumulating leads to a decrease of pH , the efficiency of the anaerobic treatment has already decline

99、d markedly ( Gu , 1993) . Therefore , it is more important to control VFA than to control pH in anaerobic system. The alkalinity is regarded as an important role to resist the VFA accumulation so as to increase pH in an

100、anaerobic system</p><p>　　(Kroeker , 1979 ; Gu , 1993) . Alkalinity of the wastewater is defined as the gross substance which can react rationally with strong acids. Alkalinity includes many kinds of alkali

101、components such as carbonates , bicarbonates , hydrates and organic base. They are called as total alkalinity in the wastewater (Editorial Board of Environment Protection Bureau of China , 1997) . The TPD wastewater has